A window regulator for a vehicle comprises a drive unit with an electric motor and a gear system for transmitting force to the window regulator. An electronic control unit (ECU) comprising a support and a PCB is assembled to a housing of the drive unit for motor control. The ECU comprises also a motor connector for the electric connection to the shaft of the motor and a vehicle connector (plug with connection pins) for the connection to the vehicle wiring system. As the window regulator is mounted inside the vehicle door which is a wet area, the assembly between the drive unit and the ECU must be watertight, which implies a watertight coupling between the support of the ECU and the housing of the drive unit but also a watertight mounting of the connection pins to the support because humidity can reach the PCB of the ECU through the connection pins. A solution to guarantee the sealing of the connection pins can be to over-mold the connection pins with an elastomeric material what means that the pins have to be mounted first on the support of the ECU, then (after over-molding the elastomer) connect, by welding, the PCB to the connection pins and finally assembly the support to the housing of the drive unit. For welding the PCB to the connection pins is necessary to have a free access to the position of the connecting pins on the support but a problem arises because the free space inside the door is reduced. The ECU is coupled to the housing in an assembly direction orthogonal to the axis of the motor because the motor connector must be orthogonal to the axis of the motor but as the space is reduced the vehicle connector usually has to be placed in a direction parallel to the shaft of the motor and orthogonal to the assembly direction which means that the vehicle connector and the motor connector are mounted on the support orthogonally to each other. For that reason and to guarantee the free access needed for welding the PCB to the pins an open configuration of the support is used, for example an L shaped support couplable to an L shaped opening of the housing in the drive unit. For assuring the watertight connection between the L shaped support and the L shaped opening of the housing, seals with multiple lips are mounted internally around the perimeter of the L shaped opening. A problem arises because the lips of the seal get placed in two different orientations in relation to the assembly direction, so the lips of the seal (during and after the coupling of the ECU) can be bended or twisted leaving gaps for to the humidity to enter, resulting in a bad sealing. FR-3024609-A1, FR-3024610-A1, WO-2004/095675, WO-2006/117265, WO-2011/058972 describe seals for L shaped openings but all use seals with multiple lips which cannot assure a proper sealing, especially in parts of the seal which are placed radially to the assembly direction.